The sooner the better IMO
I’ve not swung it for more than ...about 5 days, when I had a poor hatch (our first try), and already had some poults coming.
I raised her w the turkeys for a few weeks, until I found the ducklings I was looking for.
I wouldn’t do it that way again.
She imprinted on the turkeys, and would call them over to the duck yard when the turkeys were free ranging- and race off / away from the other ducks to the turkey yard if the ducks were out.
It took probably 6 weeks for her to realize she’s a duck.
....although she def gained street creds w the other ducks when she would charge the fence when she saw the turkeys- the other ducks were very afraid of the pterodactyls!!
Check CL, FB groups near you, etc- it’s a tough time to find a duckling but I’m sure you can!
...Metzer also might ship as few as 2, if memory serves....